Introducing the Specifications of the Metro Ethernet Forum
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Introducing the Specifications of the Metro Ethernet Forum 1 Introducing the Specifications of the Metro Ethernet Forum MEF 2 Requirements and Framework for Ethernet Service Protection MEF 3 Circuit Emulation Service Definitions, Framework and Requirements in Metro Ethernet Networks MEF 4 Metro Ethernet Network Architecture Framework Part 1: Generic Framework MEF 6 Metro Ethernet Services Definitions Phase I MEF 7 EMS-NMS Information Model MEF 8 Implementation Agreement for the Emulation of PDH Circuits over Metro Ethernet Networks MEF 9 Abstract Test Suite for Ethernet Services at the UNI MEF 10 Ethernet Services Attributes Phase I MEF 11 User Network Interface (UNI) Requirements and Framework MEF 12 Metro Ethernet Network Architecture Framework Part 2: Ethernet Services Layer MEF 13 User Network Interface (UNI) Type 1 Implementation Agreement MEF 14 Abstract Test Suite for Ethernet Services at the UNI MEF 15 Requirements for Management of Metro Ethernet Phase 1 Network Elements MEF 16 Ethernet Local Management Interface * MEF 10 * replaced MEF 1 and MEF 5 2 This Presentation • Purpose – This presentation is intended as an introduction and companion to both the MEF 3 and MEF 8 Specifications – These are the two principal specifications relating to services that carry Circuit Emulation/TM traffic across Carrier Ethernet • Audience – It is intended for Product Marketing, Engineering staff of member companies, for members of other standards bodies, Enterprise networking staff, and service providers who • Would like a quick overview of the specifications • Plan to read the specifications in detail • Other Documents – Presentations of the other specifications and an overview of all specifications is available on the MEF web site – Other materials such as white papers and case studies are also available 3 MEF Specifications Overview Circuit Emulation Service Definitions, Framework and Requirements in MEF 3 Metro Ethernet Networks Circuit Emulation Service “tunnels” TDM traffic through a Metro Ethernet Purpose network allowing inclusion of legacy networks within a Carrier Ethernet environment Equipment Manufacturers supporting devices that provide Circuit Emulation Audience over Carrier Ethernet Services. Useful for Service Providers architecting their systems. Technical Committee Service Area Implementation Agreement for the Emulation of PDH Circuits over MEF 8 Metro Ethernet Networks Gives precise instructions for implementing interoperable CES equipment that reliably transport TDM circuits across Metro Ethernet Networks while Purpose meeting the required performance of circuit emulated TDM services as defined in ITU-T and ANSI TDM standards Equipment Manufacturers supporting devices that provide Circuit Emulation Audience over Carrier Ethernet Services. Useful for Service Providers architecting their systems. Technical Committee Service Area 4 MEF 3: CES Framework & Requirement MEF 8: CES Implementation Agreement • Industry’s first formal definition of CES standards over Ethernet • A services description – Types of TDM services offered over Metro Ethernet, – PDH and SONET/SDH – DS1E1, DS3/E3, OC-3/STM-1, OC-12/STM-4 • A requirement document – Comprehensive CES requirements for providing TDM services over Ethernet – SLA service quality parameters as specified by the ITU for TDM services • An implementation agreement for Ethernet – Practical agreement as to how to implement the CES over Ethernet 5 What is Circuit Emulation Service over Carrier Ethernet? • Circuit Emulation Service “tunnels” TDM traffic through a Metro Ethernet network – packet network “emulates” a circuit-switched network, re-creating the TDM circuit at the far end – invisible to TDM source and destination equipment – runs on a standard Ethernet Line Service (E-Line) Metro Ethernet Network TDM Circuits TDM Circuits (e.g. T1/E1 Lines) (e.g. T1/E1 Lines) TDM Pipe 6 MEF 3 TDM Circuit Emulation • Support Traditional PDH/SONET/SDH hand-offs to existing customer voice equipment • Allow Interworking onto Ethernet EVCS across the MEN. Point-to-point EVCs TSP / TDM CES IWF CE T3 TSP / CES IWF TDM CE T3 TSP / TDM CES IWF CE T1 MEN TSP / CES IWF TDM TSP / CE TDM CES IWF OC3 CE T1 Types: 1)Unstructured - all bits in must be sent across to the destination 2) Structured - Requires only sending TDM payloads not the over head 7 Circuit Emulation Services Relationship to the Metro Ethernet Network TDM TSP CES Service Provider CES TSP TDM CE (optional) IWF Network IWF (optional) CE TDM Link TDM Link EFT EFT MEN EVC UNI-C UNI-N UNI-N UNI-C ETH Access Link ETH Access Link TDM Subscriber Ethernet UNI Ethernet UNI TDM Subscriber Demarcation Demarcation • CES functions in relation to those specified by the MEF for the MEN 8 Functions Defined PDH TSP Mapper IWF To CE IWF To MEN IWF ECDX EFTF TSP SDH Framer • TSP - Optional TDM mux/demux function –prior to Ethernet interworking • IWF - Interworking function of TDM to Ethernet frames • ECDX - Identifier function for proper forwarding and demultiplexing • EFTF –Addressing and FCS functions. 9 Functions applied TDM Service CES TDM CES IWF Type CES Payload Adapted Ethernet Interface Interface Payload Interface TSP Customer (optional) CES IWF TDM IWF ECDX EFTF Service (e.g. framing, MEN mux/demux) IWF DS1 (T1), E1, CES Control Word Ethertype Destination Addr. DS3 (T3), E3, RTP (optional) ECID Source Address Nx64 CES Control Word Ethertype TDM Payload RTP (optional) ECID CES Control Word TDM Payload RTP (optional) TDM Payload FCS • ECDX as shown is effectively a multiplexing function allowing multiple CES circuits to share a single EVC 10 Functional Layering, and mapping onto encapsulation headers Destination Address Ethernet Services Layer Source Address VLAN tags (optional) Ethertype Emulated Circuit Identifier (ECID) Adaptation Function CESoETH Control Word RTP (optional) CES Application Data TDM Payload • Treats the MEN as a “virtual wire” between two TDM networks 11 MEF Service Definitions • TDM Line Service (T-Line): – Application: Leased line replacement Customer Customer Premises CESoETH Premises TDM CES Ethernet Metro Ethernet Ethernet CES TDM IWF Network IWF E-Line Ethernet Service Ethernet UNI UNI TDM subscriber Service Provider Network TDM subscriber demarcation demarcation 12 MEF Service Definitions • TDM Access Line Service (TALS): – Application: Access to a remote network (e.g. PSTN) Customer Premises CESoETH TDM CES Ethernet Metro Ethernet Ethernet CES TDM IWF Network IWF PSTN E-Line Ethernet Service Ethernet UNI UNI TDM subscriber Service Provider Network TDM Network demarcation Interface 13 MEF Service Definitions • Customer-Operated CES: – Application: Toll-bypass Customer Customer Premises CESoETH Premises TDM CES Ethernet Metro Ethernet Ethernet CES TDM IWF Network IWF E-Line Ethernet UNI and Service Ethernet UNI and subscriber subscriber demarcation demarcation Service Provider Network 14 Structured Vs Unstructured CES 15 TDM services supported (MEF 3) Unstructured TDM TDM Service Interface Structured TDM Service Structured TDM Service Granularity Service DS1 Yes Yes Nx64 kbit/s DS3 Yes Yes DS1, Nx64 kbit/s E1 Yes Yes Nx64 kbit/s E3 Yes Yes E1, Nx64 kbit/s, DS0 OC-1 Yes Yes STS-1, VT-1.5, VT-2 OC-3 Yes Yes STS-1, VT-1.5, VT-2 OC-3c Yes Yes STS-3c STM-1 Yes Yes VC-11 (DS1), VC-12 (E1), VC-3 (DS3, E3, other) STM-1c Yes Yes VC-4, VC-3, VC-11, VC-12 VT-1.5 (DS1), VT-2 (E1), OC-12 Yes Yes STS-1 (DS3, E3, other), STS-3c OC-12c Yes Yes STS-12c VC-11 (DS1), VC-12 (E1), STM-4 Yes Yes VC-3 (DS3, E3, other), VC-4 STM-4c Yes Yes VC-4-4c 16 MEN CoS Performance Parameters To ensure proper CES IWF operation service quality: • Ethernet Frame Delay should be minimized – to meet MEF 5 defined parameters • Ethernet Frame Delay Variation – MEN EVCS jitter up to 10 ms max • Ethernet Frame Loss – ESR and SESR should meet TDM requirements • Network availability – should meet 99.95% TDM requirement 17 PDH Interoperability Agreement –MEF 8 Specifies Interoperability requirements for: • Connectivity • Timing • Signaling • MEN performance criteria • MEN services OAM 18 Emulated Circuit Identifier 0 19 20 31 Emulated Circuit Identifier (ECID) (20 bits) Reserved (set to 0x102) ECID • – identifies the emulated circuit being carried. • Separates the identification of the emulated circuit from the Ethernet layer, – allowing the MEN operator to multiplex several emulated circuits across a single EVC where required. • This is added by the ECDX. 19 CESoETH control word 0 1 2 3 4 5 6 7 8 9 10 15 16 31 Reserved M FRG LEN (Length) L R SN (Sequence Number) (16 bits) set to zero (2 bits) (2 bits) (6 bits) (12 bits) • Provides sequencing and signaling of defects – such as AIS of the TDM circuit, or packet loss detected in the MEN. • This is added by the CES IWF. 20 Standards for Synchronization E1 standards (2.048 Mbps) T1 standards (1.544 Mbps) • Traffic interface • Traffic interface (G.823, Table 2) (T1.403, section 6.3.1.2) – 18 s over 1000s – 8.4 s over 900s – 18 s over 24 hours Central Remote Customer Office Terminal Premises PRS TDM CESoP CESoP PSTN PSN Equipment IWF IWF T1/E1 T1/E1 CES induced wander < 18 s Max. end-to-end wander (traffic interface) 18 s 21 Timing Service sync trail Transport Provider - A Provider - B Provider - C sync trail Transport Timing Transport Timing Transport Timing SDIWF SDIWF SDCE SDTDM SDTDM SDCE PSTN MEN CE1 IWF IWF CE2 TSP TSP SDTDM SDED Service Timing • Synchronous services require timing be provided – Line, through, external or internal timing mode options • Applies to structure aware only • Synchronization. – the clock